基于RANS的跨海桥梁高桩承台波浪作用数值模拟

极端波浪荷载给跨海桥梁带来了严峻的挑战,为了探究波浪对跨海桥梁高桩承台的冲击作用,基于雷诺时均Navier-Stokes方程(RANS)和k-ω湍流方程,建立波浪与高桩承台相互作用三维数值模型,采用流体体积法(VOF)捕捉自由液面,研究承台受到的水平及竖向波浪力时程特性、承台周围流场以及净空对波浪荷载的影响规律。研究结果表明:承台水平波浪力随着净空的减小而增大,水平正向波浪力大于水平负向波浪力;承台受到的竖向向上波浪力随着净空的增加先增大后减小,当净空为零时达到最大值。当净空大于零时,向上的波浪力大于向下的波浪力,而当净空小于零时,向上的波浪力小于向下的波浪力。

Numerical Simulation of Wave Forces on Elevated Pile Cap of Sea-crossing Bridges Based on RANS

The extreme wave loading poses serious challenges to sea-crossing bridges. In order to investigate wave slamming effects on the elevated pile cap of sea-crossing bridges, three dimensional numerical model of wave-structure interaction is established on the basis of Reynolds Average Navier-Stokes equation(RANS) and turbulent equation, and the volume of fluid method(VOF) is adopted to capture free surface of the fluid. This paper studies the characteristics of horizontal and vertical wave forces on the cap, the flow field around the cap and the influence of clearance height on wave load. The results of the study show that: the horizontal wave forces increase with the decrease of clearance height, and forward horizontal wave force is greater than backward horizontal wave force. The uplift vertical wave forces increase first and then decrease as the clearance height increases, and its maximum value is reached when clearance height is zero. The uplift vertical wave forces are larger than the downward vertical wave forces when clearance height is greater than zero and smaller when clearance height is less than zero.